Some tests in the test suite may contain errors.
Please check the latest version of the
CSS Backgrounds 3 specificationand its errata
before assuming a failure is due to an implementation bug and
not a test suite bug.

In time we hope to correct all errors and extend this test suite to
cover all of CSS Backgrounds 3. Your help is welcome in this effort.
The appropriate mailing list for submitting tests and bug reports is
public-css-testsuite@w3.org.
More information on the contribution process and test guidelines is
available on the wiki
page.

XHTML 1.1 tests with all images converted from PNG to JPEG
and formatted with headers and footers to ease testing of
embedded printer software. This is not a canonical format,
and some tests may fail due to the format conversion that
would otherwise pass in the above XHTML 1.1 format.

The UA is set to print background colors and, if it supports graphics,
background images.

The UA implements reasonable page-breaking behavior; e.g., it is assumed
that UAs will not break at every opportunity, but only near the end of
a page unless a page break is forced.

The UA implements reasonable line-breaking behavior; e.g., it is assumed
that spaces between alphanumeric characters provide line breaking
opportunities and that UAs will not break at every opportunity, but only
near the end of a line unless a line break is forced.

Uncommon Assumptions

In addition, some of the tests make one or more of the following
assumptions:

The device is a full-color device.

The device has a viewport width of at least 640px (approx).

The resolution of the device is 96 CSS pixels per inch.

The UA imposes no minimum font size.

The 'medium' font-size computes to 16px.

The initial value of 'color' is black.

The canvas background is white.

The user stylesheet is empty (except where indicated by the tests).

The device is interactive and uses scroll bars.

The tests that need these assumptions to be true have not yet been
marked, but it is likely that we will add a way to identify these
tests in due course. Tests should avoid relying on these assumptions
unless necessary.